• Honam Mathematical Journal
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• v.42 no.1
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• pp.63-74
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• 2020

In this paper firstly, Some properties were given about metallic Riemannian structure on (1, 1)-tensor bundle. Secondly, the Tachibana and Vishnevskii operators were applied to vertical and horizontal lifts with respect to the metallic Riemannian structure on (1, 1)-tensor bundle, respectively.

• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.47-58
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• 2001

Of all the site logistics technologies in high-rise building construction, both vertical and horizontal move plan, are the most imperative factors. And the horizontal plan follows lift-up plan as of the vertical plan. However though it may be, temporary lifts on site are numbered by heuristic formulas. The quantity of finishing material cannot be converted into lift-up load per finishing material. The lift-up plan cannot be evaluated the feasibility for finishing material move plan by a reasonable evaluation methodology. The horizontal plan is far from the vertical one. And the information as an input data for the horizontal plan is devoid of package unit size, length, and volume per finishing material. These can hardly result in reasonable and detail decision on how much to use temporary lifts, how long to use these, and where to deposit each finishing material. Therefore, this study is to suggest a decision-making model that can integrate vertical and horizontal material move plan in high-rise building construction and make a decision the plans systematically. And the study is to explain the concept, methodology, and contents of the model applied to a virtual project, named as MT 130 (Millennium Tower 130). By the model, the planner can shift his/her thinking framework on site logistics management products-oriented Into process-oriented. He/she can manage a project by the framework as system thinking, evaluate the feasibility of a lift-up plan, and decide the horizontal plan integrated with the lift-up.

• Journal of Biosystems Engineering
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• v.8 no.2
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• pp.1-10
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• 1983

The resulting characteristics of vibrations show different patterns for the various oscillating mechanisms. These vibrations causes troublesome operation problems for the operators and sometimes for the machines. Furthermore, in some cases the practical usage of this oscillating mechanism is constrained by its mechanical conditions. In this study, a balanced oscillating tillage tool with triple blades having different acting area was designed. The horizontal and vertical oscillating accelerations and draft power requirement due to the various travel speeds, lift angles, amplitudes and oscillating frequencies were investigated in a laboratory soil bin with a soil having invariable properties. The results obtained are summarized as follows: 1. Overall, the horizontal acceleration decreased as the oscillating frequency and amplitude decreased. But the increase in travel speed caused the decrease horizontal acceleration. The blade with the lift angle of $30^{\circ}$ exhibited the lowest value of horizontal acceleration among the blades tested. 2. For the vertical acceleration, the fluctuating trend of oscillating acceleration was similar to the trend of the horizontal acceleration. 3. The draft power requirement decreased as the amplitude and oscillating frequency increased. But the increase in travel speed caused the increase in draft power requirement. The blade with the lift angle of $10^{\circ}$ showed the lowest value of draft power requirement among the blades tested.

• Communications of the Korean Mathematical Society
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• v.36 no.1
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• pp.135-147
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• 2021

In this paper, we introduce the harmonicity of a covector field on a Riemannian manifold (M, g) to its cotangent bundle T∗ M equipped with g-natural metric. Afterward we also construct some examples of harmonic covector fields.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.1
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• pp.91-98
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• 2008

One of the two spindles in the X-lift fractured suddenly during normal operation. The fracture occurred at the notch where the bending moment might be the maximum. Macrofractographic features associated with rotating-bending fatigue are evident on the fracture surface. The 3-D finite element analysis of the X-lift reveals that the spindle rotated under bending. The measured surface strain of the spindle varies cyclically as the spindle rotates. It supports that the spindle rotated under bending. The X-lift is not perfectly symmetrical with respect to both the horizontal and the vertical plane. The slightly unsymmetrical deformation can cause the bending of the spindle.

• Kyungpook Mathematical Journal
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• v.61 no.4
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• pp.791-803
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• 2021

Earlier investigators have made detailed studies of geometric properties such as integrability, partial integrability, and invariants, such as the fundamental 2-form, of some canonical f-structures, such as f³ ± f = 0, on the frame bundle FM. Our aim is to study metallic structures on the frame bundle: polynomial structures of degree 2 satisfying F² = pF +qI where p, q are positive integers. We introduce a tensor field F_α, α = 1, 2…, n on FM show that it is a metallic structure. Theorems on Nijenhuis tensor and integrability of metallic structure F_α on FM are also proved. Furthermore, the diagonal lifts g^D and the fundamental 2-form Ω_α of a metallic structure F_α on FM are established. Moreover, the integrability condition for horizontal lift F_α^H of a metallic structure F_α on FM is determined as an application. Finally, the golden structure that is a particular case of a metallic structure on FM is discussed as an example.

• Communications of the Korean Mathematical Society
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• v.35 no.3
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• pp.1019-1035
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• 2020

In this paper, we introduce the deformed-Sasaki metric on the tangent bundle TM over an m-dimensional Riemannian manifold (M, g), as a new natural metric on TM. We establish a necessary and sufficient conditions under which a vector field is harmonic with respect to the deformed-Sasaki Metric. We also construct some examples of harmonic vector fields.

• Communications of the Korean Mathematical Society
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• v.36 no.3
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• pp.575-592
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• 2021

In this paper, we introduce the Berger type deformed Sasaki metric on the cotangent bundle T^*M over an anti-paraKähler manifold (M, 𝜑, g) as a new natural metric with respect to g non-rigid on T^*M. Firstly, we investigate the Levi-Civita connection of this metric. Secondly, we study the curvature tensor and also we characterize the scalar curvature.

• The Mathematical Education
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• v.29 no.1
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• pp.63-68
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• 1990

Let M be a differentiable manifold, TM its tangent bundle and FM its frame bundle. The theory of complete lifts and Horizontal lifts to FM of vector fields on M ahs been studied by many authors. Tn this paper, vertical lifts of functions vector fields md 1-forms on M to FM are studied.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.2
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• pp.113-121
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• 2005

How to extimate the angle of attack of a vertical V-type cambered otter board was described. A three-dimensional semi-analytic treatment of a towing cable system was applied to the field experiments of a midwater trawl obtained by the Scanmar system. Also the equilibrium condition of the horizontal component and vertical component of forces and moment around the otter board was used. When the warp length was 300m long and the towing speed was between 2.61 and 3.86 knots, the estimated angle of attack of the otter board was ranged between $24.7^{\circ}$ and $26.2^{\circ}$, though the maximum lift force was at the angle of attack $22^{\circ}$.